Comparison of Effective Dose and Image Quality for Newborn Imaging on Seven Commonly Used CT Scanners

2016 ◽  
Author(s):  
Hannele Niiniviita ◽  
Timo Kiljunen ◽  
Jarmo Kulmala
Keyword(s):  
Image Quality ◽  
Effective Dose ◽  
Ct Scanners

Using 100- instead of 120-kVp computed tomography to diagnose pulmonary embolism almost halves the radiation dose with preserved diagnostic quality

2010 ◽  
Vol 51 (3) ◽  
pp. 260-270 ◽  
Author(s):  
Peter Björkdahl ◽  
Ulf Nyman
Keyword(s):  
Computed Tomography ◽  
Pulmonary Embolism ◽  
Image Quality ◽  
Radiation Dose ◽  
Effective Dose ◽  
Ct Number ◽  
Subjective Image Quality ◽  
Diagnostic Quality ◽  
X Ray ◽  
Tube Potential

Background: Concern has been raised regarding the mounting collective radiation doses from computed tomography (CT), increasing the risk of radiation-induced cancers in exposed populations. Purpose: To compare radiation dose and image quality in a chest phantom and in patients for the diagnosis of pulmonary embolism (PE) at 100 and 120 peak kilovoltage (kVp) using 16-multichannel detector computed tomography (MDCT). Material and Methods: A 20-ml syringe containing 12 mg I/ml was scanned in a chest phantom at 100/120 kVp and 25 milliampere seconds (mAs). Consecutive patients underwent 100 kVp ( n = 50) and 120 kVp ( n = 50) 16-MDCT using a “quality reference” effective mAs of 100, 300 mg I/kg, and a 12-s injection duration. Attenuation (CT number), image noise (1 standard deviation), and contrast-to-noise ratio (CNR; fresh clot = 70 HU) of the contrast medium syringe and pulmonary arteries were evaluated on 3-mm-thick slices. Subjective image quality was assessed. Computed tomography dose index (CTDIvol) and dose–length product (DLP) were presented by the CT software, and effective dose was estimated. Results: Mean values in the chest phantom and patients changed as follows when X-ray tube potential decreased from 120 to 100 kVp: attenuation +23% and +40%, noise +38% and +48%, CNR −6% and 0%, and CTDIvol −38% and −40%, respectively. Mean DLP and effective dose in the patients decreased by 42% and 45%, respectively. Subjective image quality was excellent or adequate in 49/48 patients at 100/120 kVp. No patient with a negative CT had any thromboembolism diagnosed during 3-month follow-up. Conclusion: By reducing X-ray tube potential from 120 to 100 kVp, while keeping all other scanning parameters unchanged, the radiation dose to the patient may be almost halved without deterioration of diagnostic quality, which may be of particular benefit in young individuals.

scholarly journals Image Quality and Dose Reduction by Dual Source Computed Tomography Coronary Angiography: Protocol Comparison

Dose-Response ◽  
2018 ◽  
Vol 16 (4) ◽  
pp. 155932581880583 ◽  
Author(s):  
Ernesto Forte ◽  
Serena Monti ◽  
Chiara Anna Parente ◽  
Lukas Beyer ◽  
Roberto De Rosa ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Coronary Angiography ◽  
Effective Dose ◽  
Computed Tomography Coronary Angiography ◽  
Correct Selection ◽  
Dual Source ◽  
Group A ◽  
Noise Ratio ◽  
Dual Source Computed Tomography

Purpose: To compare image quality and radiation dose among different protocols in patients who underwent a 128-slice dual source computed tomography coronary angiography (DSCT-CTCA). Methods: Ninety patients were retrospectively grouped according to heart rate (HR): 26 patients (group A) with stable HR ≤60 bpm were acquired using high pitch spiral mode (FLASH); 48 patients (group B) with irregular HR ≤60 bpm or stable HR between 60 and 70 bpm using step and shoot mode; and 16 patients (group C) with irregular HR >60 bpm or stable HR ≥70 bpm by retrospective electrocardiogram pulsing acquisition. Signal to noise ratio (SNR) and contrast to noise ratio (CNR) were measured for the main vascular structures. Moreover, the dose-length product and the effective dose were assessed. Results: Both SNR and CNR were higher in group A compared to group C (18.27 ± 0.32 vs 11.22 ± 0.50 and 16.75 ± 0.32 vs 10.17 ± 0.50; P = .001). The effective dose was lower in groups A and B (2.09 ± 1.27 mSv and 4.60 ± 2.78 mSv, respectively) compared to group C (9.61 ± 5.95 mSv) P < .0001. Conclusion: The correct selection of a low-dose, HR-matched CTCA scan protocol with a DSCT scanner provides substantial reduction of radiation exposure and better SNR and CNR.

scholarly journals Application of Different methods for Reducing Radiation Dose to Breast during MDCT

2018 ◽  
Author(s):  
M Keshtkar ◽  
V Saba ◽  
M A Mosleh-Shirazi
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Low Income ◽  
Low Income Countries ◽  
Radiological Protection ◽  
Reconstruction Algorithms ◽  
Radiation Induced Cancer ◽  
Bismuth Shielding ◽  
Ct Scanners ◽  
Radiosensitive Organs

The increased use of computed tomography (CT) and its high radiation dose have led to great concerns about its potential for radiation induced cancer risks. Breast is a radiosensitive tissue based on tissue weighting factors assigned by the International Commission on Radiological Protection (ICRP). Moreover, the dose is maximal on the surface of the patient. Therefore, strategies should be taken to reduce radiation dose to the breast. The aim of this review is to introduce methods used for reducing radiation dose to breast in thoracic CT and review related performed studies. The literature indicates that bismuth shielding increases image noise and CT numbers as well as introducing streak artifacts. Tube current modulation (TCM) technique and iterative reconstruction algorithms can provide some levels of dose reduction to radiosensitive organs and superior image quality without the disadvantages of bismuth shielding. However, they are not available on all CT scanners, especially in low-income countries. Such centers may have to continue using bismuth shields to reduce the dose until these superior techniques become available at lower costs in all CT scanners. Furthermore, design and manufacture of new shields with the lower impact on image quality are desirable.

An Automatic System for Analyzing Phantom Images to Determine the Reliability of PET/SPECT Cameras

2015 ◽  
Author(s):  
Miri Weiss Cohen ◽  
John A. Kennedy ◽  
Archil Pirmisashvili ◽  
Gleb Orlikov
Keyword(s):  
Quality Control ◽  
Image Quality ◽  
Spatial Resolution ◽  
Automatic System ◽  
Quality Parameters ◽  
Tomographic Image ◽  
Performance Parameters ◽  
Pet Ct ◽  
Ct Scanners

This paper describes an automatic system for analyzing phantom images from two types of PET/CT scanners. The system was developed for the purpose of obtaining tomographic image quality parameters, which determine a number of different performance parameters, primarily scanner sensitivity, tomographic uniformity, contrast and spatial resolution. The system provides a method for generating and altering image masks used for the analysis of PET images, which are then automatically aligned with the PET data. The system automatically generates Quality Control (QC) reports and is currently being used at clinical PET/CT center.

Comparison study of image quality and effective dose in dual energy chest digital tomosynthesis

2018 ◽  
Vol 148 ◽  
pp. 112-120
Author(s):  
Donghoon Lee ◽  
Sunghoon Choi ◽  
Haenghwa Lee ◽  
Dohyeon Kim ◽  
Seungyeon Choi ◽  
...  
Keyword(s):  
Image Quality ◽  
Effective Dose ◽  
Dual Energy ◽  
Digital Tomosynthesis ◽  
Comparison Study

Acquisition time, radiation dose, subjective and objective image quality of dual-source CT scanners in acute pulmonary embolism: a comparative study

2020 ◽  
Vol 30 (5) ◽  
pp. 2712-2721 ◽  
Author(s):  
Waleed Abdellatif ◽  
Eric Esslinger ◽  
Kevin Kobes ◽  
Amanda Wong ◽  
Jennifer Powell ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Image Quality ◽  
Radiation Dose ◽  
Comparative Study ◽  
Acute Pulmonary Embolism ◽  
Acquisition Time ◽  
Dual Source Ct ◽  
Dual Source ◽  
Ct Scanners

Towards image quality, beam energy and effective dose optimisation in digital thoracic radiography

2001 ◽  
Vol 11 (5) ◽  
pp. 870-875 ◽  
Author(s):  
J. H. Launders ◽  
A. R. Cowen ◽  
R. F. Bury ◽  
P. Hawkridge
Keyword(s):  
Image Quality ◽  
Effective Dose ◽  
Beam Energy ◽  
Thoracic Radiography ◽  
Dose Optimisation

scholarly journals Optimizing a perfusion CT protocol for head and neck cancer

2017 ◽  
Vol 3 (2) ◽  
pp. 591-594 ◽  
Author(s):  
Anja Stüssi ◽  
Marta Bogowicz ◽  
Verena Weichselbaumer ◽  
Patrick Veit-Haibach ◽  
Oliver Riesterer ◽  
...  
Keyword(s):  
Head And Neck Cancer ◽  
Image Quality ◽  
Head And Neck ◽  
Effective Dose ◽  
Neck Cancer ◽  
Image Resolution ◽  
Slice Thickness ◽  
Organ Doses ◽  
Scanning Protocol ◽  
Optimized Protocol

AbstractPerfusion computed tomography (CTP) images tumor angiogenesis and can assess tumor aggressiveness. However, the CTP examinations are dose intensive. This study aimed to optimize a routinely used CTP protocol for the head and neck region in oncology in order to reduce the effective dose to the patient and simultaneously achieve the same image quality.The Alderson phantom was scanned on a GE Revolution CT scanner. A scan with our standard protocol for head and neck cancer patients was used (100kV, 80mAs, 5mm slice thickness and backprojection algorithm) and in seven predefined regions (ROI) the signal to noise ratio (SNR) was measured. For the dose optimized protocol, the tube voltage was lowered and the mAs adaptation protocol was used. To improve image quality different percentage of an adaptive statistical iterative reconstruction (ASiR) was applied. For a better resolution we set the slice thickness to 2.5 mm. The mAs adaption range and the percentage of the ASiR reconstruction were varied until we found a combination with the same median SNR in the seven defined ROIs as for our old protocol. For the old and the optimized protocol dose measurements were performed using 25 LiF-TLDs. Organ doses were calculated and the effective dose was determined based on the weighting factors of ICRP103.The optimized scanning protocol used a voltage of 80kV, a mAs range between 15 and 80, a noise level of 10%, and 50% ASiR reconstruction. The median SNR ratio was slightly better (14% better SNR) with the new protocol. An effective dose of 8 mSv was measured with the original protocol and 4 mSv with the optimized scanning protocol. For organs in the scanning field the dose was reduced by a factor of 2 and outside the field by a factor of 2.2.Advanced reconstruction algorithms allow a significant dose reduction and an improvement of image resolution, while maintaining the image quality.

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